Characteristics of Natural Convection Heat Transfer in a Horizontal Cylindrical Eccentric Annuli for Heated Outer Tube and Cooled Inner Tube

This study was researched by a numerical analysis and experiment, on a natural convection heat transfer in a horizontal cylindrical eccentric annuli, which heated outer tube and cooled inner tube. The inner tube shifted to vertical upper side, slant upper side 45 degrees, horizontal side, slant lower side 45 degrees and vertical lower side, respectively. The numerical analysis was performed by changing the shift direction, eccentricity and Rayleigh number as parameters. Results obtained for different conditions are presented as temperature profiles, flow patterns, local Nusselt number and total heat transfer. It was presented that the heat transfer enhancement effect or heat transfer obstruction effect on the total heat transfer were affected by shift direction and eccentricity.